cats do get colds just like people do. the thing to watch out for is if that clear liquid coming from the eye develops some coloration, or pus consistency, or swelling.
THEN rush kitty to the vet ASAP. Any eye infection from illness can have serious consequences, leading to possible blindness.
If kitty gets a stuffy nose and stops eating, then you'll possibly have to take steps in feeding kitty.
...but, probably it's just a common cold, that will pass, as they tend to do. :)